Stabilized chlorofluoroalkanes



United States Patent 7" This invention relates to chlorofiuoroalkanecompositions and particularly to certain chlorofluoroalkanes containingminor proportions of compounds which inhibit reaction of thechlorofiuoroalkanes with primary and secondary alcohols.

" 'Although it has been known for several years that perfluorinatedolefins are sensitive to attack by oxygen, saturated fluorine-containingperhalogenated hydrocar- ;bons are considered to be stable underordinary conditions and, indeed, oxidation and hydrolysis, which causethe decomposition of other halogenated hydrocarbons, have no effect onthe fluorine-containing compounds.

Recently, it Was reported that certain fluorine-containingperhaloalkanes, including trichlorofluoromethane, react fairly rapidlywith alkanols in the presence of silver ions to'give hydrogen halide, analdehyde or ketone (depending on whether a primary or secondary alcoholis involved) and a reduced halogenated organic compound wherein onechlorine or bromine has been replaced by hydrogen [l-leberling, In, etal., J.A.C.S., 78, 5433 (1956)]. The silver ion naturally reacts withthe hydrogen halide to precipitate silver halide. Silver ion was shownto catalyze the reaction but not to be a necessary reactant, albeit thereaction is very much slower without silver ion. The reaction was notreported for trichlorofluoromethane in the absence of silver ions. Thereaction that occurs between trichlorofiuoromethane and ethyl alcohol isas follows:

This reaction does not appear to occur with more highly fluorinatedchlorofiuoromethanes such as dichlorodifluoromethane. The reactionoccurs only in the presence of primary and secondary alcohols; tertiaryalcohols being unreactive, and is briefly inhibited by hydroquinone. Inthe pure state, trichlorofluoromethane is quite stable.

In the past, the reaction of trichlorofluoromethaue with alcohols was oflittle consequence since these two compounds were seldom used together.Recently, certain aerosol formulations which involve the use oftrichlorofiuorornethane and ethyl alcohol (e.g. aerosol hair sprays)have become large scale commercial products and the above describedreaction has become a serious problem. Not only does the product,acetaldehyde, have an objectionable odor and form colored andodoriferous condensation products, but the hydrogen chloride serious- 1yattacks the metallic container forming insoluble metal salts andhydrogen. The formaton of hydrogen leads to a rapid increase in pressurewithin the container which, in combination with the weakening of thecontainer due to corrosion, often leads to bulging and rupture of theaerosol container. The other product of the reaction,dichloromonofluoromethane, also leads to a pressure increase within thecontainer but this is not nearly so serious as that due to hydrogen.Although hydrogen chloride is formed, both in the reaction ofchlorofluoroalkanes with alcohols and in the decomposition of somechlorinated hydrocarbons, the cause of the formation of the hydrogenchloride is fundamentally different. The chlorofluoroalkanes form HClonly in the presence of primary and secondary alcohols and are stable onstorage under conditions which cause chlorinated hydrocarbons todecompose.

3,085,116 Patented Apr. 9, 1963 The subject of inhibiting the reactionof trichlorofiuoromethane with an alcohol must be considered from theviewpoint of the end use. The trichlorofiuoromethane is used as thepropellant, usually as one member of a propellant mixture, and thealcohol usually is used as the solvent for a solid or liquid materialwhich is to be dispensed via an aerosol system. The inhibitor used must,therefore, not be objectionable in the end use intended. Most of theseaerosols come in contact with human belugs and the inhibitor must beharmless to humans. The products of the reaction, being colored,odoriferous and acidic, are objectionable and harmful to humans andtherefore their formation must be prevented. The everpresent possibilityof violent rupture of the aerosol container due to hydrogen pressure isalso dangerous to humans and must be prevented. There is thus good causenot only to find inhibitors for the reaction but also to find inhibitorswhich are harmless to humans.

It is known now that the reaction between alcohols andtrichlorofluorornethane takes place most rapidly when air is essentiallyabsent. Since air itself inhibits the reaction, almost any compound willinhibit the reaction of sufficient air is present but only certaincompounds will inhibit the reaction if air is essentially absent. Whileit may seem feasible to inhibit the reaction by merely leaving air inthe aerosol container, this procedure is not tenable from a practicalviewpoint. It does not appear to be possible to leave a controlledamount of air in such a system. Uncontrolled amounts of air aredangerous due to the rather limited pressure service range of aerosolcontainers and the possibility that the uncontrolled amount of air maycause the pressure to exceed the strength of the container (cf. theresult from too much hydrogen). Air also has a deleterious effect on thecomponents of many aerosol formulations, e.g. perfumes.

Trichlorotrifluoroethanes and tetrachlorodifiuoroethanes are frequentlyemployed in admixture with primary and secondary alcohols as solventmedia for cleaning, e.g. degreasing, dewaxing, and the like, ofelectronic equipment, compressors, photographic film, lithographicplates, typewriters, sensitive instruments, gauges, and the like, andfor removing varnish, rosin, and like coatings from printed electricalcircuits. In such uses, the formation of hydrogen chloride and ofcolored and odoriferous condensation products are objectionable andharmful to humans and to the equipment being cleaned. There fore, it isimportant to inhibit the reaction of these chlorofiuoroalkanes withalcohols in these uses.

The chlorofluoroalkanes, e.g. CFC13, C F Cl and C F Cl react withprimary and secondary polyols in the same manner as they do with primaryand secondary monohydric alcohols, i.e. to form hydrogen chloride, analdehyde or ketone, and a reduced haloalkane, i.e. C2HF3C12 01'C2F2HC13. The mechanism Of the reaction with polyols is the same as thatwith the monohydric alcohols. Polyols are extensively used incombination with trichlorofluoromethane and trichlorotrifiuoroethane forpreparing urethane foams by reaction with polyfunctional isocyanates.The products, formed by the reaction of these chlorofluoroalkanes withpolyols, adversely affect the properties of the urethane foams which areprepared from them as well as interfering with the foam producingreaction. For this reason, it is desirable to also inhibit the reactionbetween the above chlorofiuoroalkanes and polyols.

It is an object of this invention to provide means to inhibit thereaction between primary and scondary alcohols andtrichlorofluoromethane, trichlorotrifluoroethanes andtetrachlorodifluoroethanes. A particular object is to provide inhibitorsfor such purposes which are volatile,

non-acidic, relatively non-toxic, relatively inexpensive, and which areeffective in small concentrations and for reasonably long periods oftime. Other objects are to provide new compositions of matter and toadvance the art. Still other objects will appear hereinafter.

The above and other objects may be accomplished in accord with thisinvention which comprises a composition resistant to reaction withprimary and secondary alcohols which consists essentially of achlorofluoroalkane of the group consisting of trichlorofluoromethane,trichlorotrifluoroethanes and tetrachlorodifluoroethanes and from about0.1% to about by weight of a mononitroalkane of l to 3 carbon atoms.

It has been found that, if the aforesaid mononitroalkanes are presentwhen the aforesaid chlorofluoroalkanes are brought into contact withprimary and secondary alcohols, the reaction normally occurring bet-weenthe chlorofluoroalkane and the alcohol is effectively inhibited forperiods of at least 6 months under ordinary storage conditions. Saidnitroalkanes are volatile, non-acidic, substantially non-toxic, low incost and are highly effective in small concentrations. They do not haveobjectionable odor or color and are not corrosive to metals and do notattack most materials with which the compositions of this invention willordinarily be brought into contact. The mechanism by which thesecompounds inhibit the reaction between the chlorofluoroalkanes and thealcohols is not known with certainty and could not be predicted.

The inhibiting effect is specific to the mononitroalkanes. Hydroquinone,2-nitro-1-butanol, free radical inhibitors, and, in general, compoundsknown to be useful for inhibiting the decomposition of chlorinatedhydrocarbons, are not useful for the purposes of this invention becauseof little or no effectiveness to inhibit the reaction, low volatility,cost, objectionable odor or color, toxicity, acidity, and like defects.

The primary and secondary alcohols include monohydric and polyhydricalcohols in which at least one alcoholic hydroxyl group is attached to aprimary or a secondary carbon atom. Inthe polyhydric alcohols, it isnotnecessary that all alcoholic hydroxyl groups be attached to primary orsecondary carbon atoms, but some of them may be attached to tertiarycarbon atoms. Usually, the alcohols involved are the neutral aliphaticalcohols that consist of carbon, hydrogen and oxygen, which may includeether or carboxy ester groups. In aerosol compositions and in solventmixtures, the alcohols involved usually are the primary and secondaryalkanols which are normally liquid, i.e. at normal temperatures andpressures. Mose usually, the alkanols are the lower alkanols, i.e.containing 1-4 carbon atoms, such as methanol, ethanol, propanol,isopropanol, n-butanol, isobutanol, secondary butanol, ethylene glycol,propylene glycol, glycerol, and the'sugar alcohols, e.g. sorbitol. Inthe preparation of urethane foams, the alcohols usually involved are theprimary and secondary polyols. The polyols are polymeric materialscontaining a plurality of alcoholic hydroxyl groups such as thepolyglycols, e.g. polyethylene glycol and polypropylene glycol, andcondensation products of alkylene oxides with sugar alcohols, e.g. thecondens'ation product of propylene oxide with sorbitol, and the like.Such polyols usually contain ether groups and may contain carboxylicester groups.

The chlorofiuoroalkanes to be used or treated in accord with thisinvention are trichlorofluoromethane, 1,1,2-trichloro 1,2,2trifiuoroethane, 1,1,1-trichloro-2,2,2-trifiuoroethane, tetrachloro 1,2difiuoroethane, and tetrachloro-2,Z-difiuoroethane. The invention ismost preferably applied to trichlorofluoromethane.

The inhibiting compounds are mononitroalkanes of 1 to 3 carbon atoms,i.e. nitromethane, nitroethane, l-nitropropane and Z-nitropropane, andmixtures of any two or more thereof. Nitromethane and nitroethane arepreferred. Nitroalkanes of more than 3 carbon atoms are less usefulbecause of. their low volatility and because they generally requireundesirably large proportions to produce the dmired prolonged inhibitingeffect.

The nitroalkane will be employed in a proportion of from about 0.1% toabout 5% by weight based on the chlorofluoroalkane. Materially smallerproportions are less effective and for shorter periods of time. Largerproportions of the nitroalkanes may be employed but are unnecessary formost purposes and tend to be uneconomical.

The nitroalkanes are soluble in both the chlorofluoroalkanes and thealcohols. Also, the chlorofluoroalkanes and the alcohols are soluble ineach other. The nitroalkane can be added to the chlorofluoroalkane, orto the alcohol, or to compositions containing either or both thechlorofluoroalkane and the alcohol. The alcohol may be mixed withanother solvent or it may be a component (e.f. a solvent) of a materialto be dispensed as an aerosol. The trichlorofluoromethane may, andusually will be a member of a mixture of propellents, the other membersof which are lower boiling (higher pressure) chlorofluoroalkanes, suchas dichlorodifluoromethane, dichlorotetrafiuoroethane,monochlorodifluoromethane, l,l-difluoroethane and octafluorocyclobutane.Sometimes, normally gaseous alkanes, such as propane, butane andisobutane are included in minor proportions in such propellent mixtures.A representative propellent mixture consists of 45% by weight oftrichlorofluoromethane, 45% by weight of dichlorodifluoromethane and 10%by weight of isobutane. It is preferred to add the nitroalkane to thechlorofluoroalkane or to a propellent mixture containing it, so that itwill be present when the chlorofluoroalkane comes into contact with oris admixed with a primary or secondary alcohol or with compositionscontaining such alcohols.

In order to more clearly illustrate this invention and the advantageousresults to be obtained thereby, examples are given hereinafter in TablesI to IX (including duplicate experiments in certain cases); togetherwith, in Table II for purposes of comparison, examples of othercompounds which are closely related or which have been disclosed in theprior art to be useful for inhibiting the decomposition of chlorinatedhydrocarbons.

In evaluating the various compounds as inhibitors in Tables I and II,the test of storing the composition for 6 months at F. was employed.This test is standard in the aerosol industry for evaluating the efiectson aerosol cans of various materials which might be used therein. Theinhibitors were evaluated on the basis of three criteria, the odor ofthe solution, the color of the solution, and corrosion of the metallicaerosol container, after storage for 6 months at 100 F.

In more detail, the testing and evaluation of the compounds asinhibitors in Tables I and II was carried out as follows:

The compound was dissolved at the desired concentration in specification39 C denatured alcohol (39-C alcohol contains 1 gallon of diethylphthalate per 100 gallons of 200 proof ethyl alcohol).Trichlorofluoromethane of the required amount) was added and then g. ofthe mixture was placed in a tin-plated steel aerosol container and theexcess trichlorofiuorornethane allowed to boil off to expel air untilthe mixture contained 70% by weight trichlorofluoromethane, theremaining 30% being the alcohol solution containing the prospectiveinhibitor in the desired concentration. The aerosol container was thencapped and allowed to stand in a constant temperature room at 100 F. forsix months. At the end of six months, the can and contents wereexamined; the color visually, the odor by comparison with a duplicate ofthe original mixture, and the pH by use of a Beckman pH meter using thecalomel and glass electrodes. The pH values determined should only becompared among themselves, the values are not directly correlatable withhydrogen ion concentration because the readings are taken in an alcoholsolution. Corrosion of the cans was evaluated 3,085,116 7 5 6 asfollows: no visual changeno corrosion; discoloration corrosion. Aprospective inhibitor was considered satisor very slight etching-slightcorrosion; visual, mild atfactory if no color or odor was produced, ifinsufiicient tack on metal, no salt deposits-moderate corrosion;corrosion took place to weaken the aerosol container, and heavy attackon metal accompanied, usually, by salt deif insuflicient hydrogen Wasformed to cause dangerously posits, bulging and/or perforation of thecansevere 5 high pressures (i.e. moderate corrosion or less).

Table I Weight Results of storage at 100 F. for six months No. Inhibitorpercent of inhibitor in 001313 pH Odor Color Corrosion 1.-..Nitromethane. 2.0 4.0 No change None.

' 1.0 4.8 d d Moderate.

0.5 5.0 Do. 0.1 8.7 0.01 3.3 0.001 II..- Nitromethane. 1.0 4.1

0.5 3.2 0.1 2.8 0.01 2.3 0.001 2.3 IIL. Nitroethane..- 1.0 2.6

0.5 3.7 0.1 3.4 0.01 2.5 0.001 1.3 IV Nitroethane.-- 1.0 3.8

0.5 3.8 0.1 3.5 0.01 1.7 0.001 V... 2-nitropro- 2.0 4.8

pane 1.0 5.5 d

0.5 5.2 do 0.1 5.2 do 0.01 4.6 Slightly pungent-- 0.001 4.5 Pungent VI-Control 0 1 Containers bulged and leaked before end of test period.

Table II Weight Results of storage at 100 F. for six months No.Inhibitor percent of inhibitor in CCl F pH Odor Color Corrosion IDiisobutylene 1.0 1. 2 Pungent II. t-Butanol 2. 0 1. 0 0.5 0- 1 0. 01 0.001

111.... Hydroquinone 0. 5

IV Nickel sulfate V-.- CHuCHaCH-CHaOH 1. 0 5. 2 Moderate.

0. 5 5.1 L0. N01 0. 1 4. 2 Severe.

0.01 0. 001 4. 3 Severe.

VI". Glyeidal methaerylate 2. 0 1. 8 Moderate. Y 1. 0 3. 5 Do. 0.5 2. 4D0. 1] 0.1 1; 5 CHrCH CHrO-C-C=CH2. 0. O1 0. 7 0. 001 1. 2

O CH;

VII-.- Terpene B; 2. 0 1. 0 0.5 0. 1 0. 01 0.001

VIII.. N -viny1 pyrrolidone 1. 0 5 0. 1 0. 01 0, 001

' TY Vinyl momma 1. 0 3. 9 r v 0.5 2.6 0. 1 2. 6 0. 01 4. 4 0. 001 3. 3

Table II-continued i v Weight Results of storage at 100 F. for sixmonths- No. Inhibitor percent of we inhibitor I I p in 001 3 pH OdorColor Corrosion X.. Vlnylldene chlorlde 2.0 4.0 No change None Slight.

1.0 4.1 Pungent. Yellow; Moderate. 0.5 5.3 do Do. 0.1 5.3 Severe. 0.010.001

XL-.. Benzotblazol 2.0 2.2 Slight.

0. 1 1. 8 Moderate. 0. 01 2.0 Do. 0. 001 1. 5 Severe.

XII... Propargyl alcohol 0.5 1

OHECGHzOH XIIL. Pentene-l 0.5

XIV-.' Pentene-2 0.5

XV--- 3-methyl-3-hydroxy-l-butyne .4... 2.0 l

(CHs)'r C(OH)CEGH XVL. Methyl vinyl lretone 2.0

XVII. 1.2-butylene'oxidc 2.0 1.0 UL 1 0. 01 0. 001

I Cans bulged and leaked before end of test period.

2 Saturated solution in alcohol.

3 Cans leaked and bulged at end of seven months.

Itwill be apparent from Table I that the compounds of this invention aresatisfactory inhibitors of the reac-- tion between thechlorofluoroalkane and the alcohol for at least six months when employedin concentrations of about 0.1% by weight or higher. At concentrationsbelow 0.1%, these compounds will inhibit the reaction compounds are notinhibitors at any useful concentration.

Unless otherwise noted, all aging tests in Examples III to IX werecarried out with mixtures of 70% 'by Weight of the polyol and 30% byweight of the chlorofluoroalkane. Also, unless otherwise specified, theinhibitor concentrations were 0.5 part per 100 parts ofpolyolchlorofluoroalkane mixture. All samples were aged in tin-platedsteel containers closed with blank tin-plated steel caps. Samples wereprepared by adding -a 25% excess of the chlorofluoroalkane and allowingthe excess to boil-oil, carrying the air within the can with it. Thecans were then capped immediately. This procedure purges most of the airpresent.

The concentration of acid in the aged mixtures (mole acid/mole CFCI wasdetermined by titration with standardized alcoholic potassium hydroxideusing alphanaphthol-benzein indicator. The concentration of reducedchlorofluoroalkane in the aged mixture (mole Samples or the agedmixtures were checked for color changes visually. Samples were alsotested for tree halide ion with silver nitrate solution. A definiteprecipitate was called positive; a milky color was called trace.

The results are shown in the following Tables III to IX, which show theeffect of storage of mixtures of inhibitors, ch-lorofluoroalkanes andeither polyol A" which is the condensation product of one mole ofsorbitol with 10 'moles'of propylene oxide (sold by Atlas Powder Companyas Atlas 62410) or a polypropylene glycol (P2000 having an averagemolecular weight of 2.000, or P400 having an average molecular weight of400). The structure of the sorbitol derivative is not certain since itis not known whether all of the propylene oxide condenses on one orseveral hydroxyl groups of the sorbitol. It is "certain that the productcontains a plurality of primary CHFCl /mole CFC1 was determined by gaschromatoand secondary hydroxyl groups as well as other linkages. Thepolypropylene glycols have the structure Lot.

Table III v [30% CFC13-70% polyol A" et130 F.-nitromethane inhibitor] Ain pn period, Mole acid/ Mole CHF 011/ Mole Acid/ Can Color Silvernitrate days mole CF01; mole CF01; mole CHFCI; corrosion test InitialFinal 0. 006 0.003 7. 8 2. 8 Trace None 7. 5 5. 9 032 0.012 7.8 1.4 0002 None 7. 5. 1 0 320 0.058 7.8 5. 6 0 012 0. 004 7.5 5.7

l Nitromethene omitted.

Table IV CFCla-% polyol A, F.-nitromethane inhibitor] Aging P period,Mole ecid/ Mole CHF Clz/ Mole Acid] Can Color Silver nitrate days moleCF01; mole CFCI: mole CHFClr corrosion test Initial Final 0 017 0.0102/1 7. 8 0 Moderate... N 0 change.. Positive. None None 7. 5 2. 7 doNegative. 0 059 0.016 3 7/1 7.8 1.0 Positive. 0 002 0. 001 1 7. 5 6. 8Negative. 0 386 0. 084 4 l 7. 8 0. 1 Positive. 0 009 0.004 2 2/1 7.5 1.7Trace.

1 Nitromethane omitted.

Table V [CFCh-polyol A"nitromethane inhibitor, F.]

Aging pH period, Mole acid/ Mole CHFClz/ Mole Acid/ Can Color Silvernitrate days mole CFC mole CFC]: mole CHFC]: corrosion test InitialFinal 0. 003 Trace 7 1 7. s 4. o No change Positive. None None 7.5 2.8do Negative. 0. 023 0. 004 6/1 7. 8 1. 2 Yel. brown.... Positive. NoneNone 7. 5 3. 2 No change. Negative. 0.051 0.310 1. 6/1 7.8 0.3 Lt. brownPositive. 0. 001 Trace 7. 5 3. 1 ....do Negative.

1 Nitromethane omitted.

Table VI [30% CFC13-70% polyolA", 194 F.nitromethane inhibitor] Aging pHperiod, Mole acid/ Mole CHFCI Mole Acid/ Can Color Silver nitrate hoursmole CFCla mole CFCla mole CHFCI: corrosion test Initial Final 0. 0390.022 1. 8/1 7. 8 0. 5 Slight plus. Yel. brown Positive. None None 7.5 1. 7 Slight No change.... Negative. 0.078 0. 044 1. 8/1 7. 8 0. 5Moderate plus- Brown Positive. 0.001 0.002 7. 5 2. 1 Slight YellowNegative.

1 Nitroniethane omitted.

Table VII [30% CFC1;70% polyol A, 194 F.nitromethane inhibitor] Cone.(weight Mole acid] Mole CHFClz/ Mole acid] Silver nitrate Aging percent)mole CF01; mole CF01; mole CHFCh Can corrosion Color test period, hrs.CHaNOz 0 0. 019 0. 004 5/1 Slight plus Positive,

0. l0 0. 012 0. 003 4/ Do.

1. 0 0. 003 Trace Negative 0 0. 394 0. 055 7. 2/1 Positive 1. 0 0.0020.001 2.0/1 V. slight S1. brown yellow. Negative.

Table VIII [30% CFCl -70% polypropylene glycol (P2000), 194F.nitromethane inhibitor] pH Aging Mole acid] Mole CHFCl Can Colorperiod, Mole CF01; mole CF01; corrosion hrs. Initial Final 24 0.009 None6. 2 0 Slight Green yellow. 24 None None 5.8 A 0.7 dn No change. 480.017 0.004 6. 2 0 Moderate.-- Greetn yellow,

DD 48 None None 5.8 0 V. slight...- No change.

Moderate.

Yellow. Brown.

1 Nitromethane inhibitor omitted.

l N itromethane omitted.

It is apparent from Tables III to IX that nitromethane inhibits thereaction between CF C1 and CFgCiCFClg and polyols, lessens corrosion anddiminishes acid formation.

It will be understood that the preceding examples have been given forillustrative purposes solely and that this invention is not limited tothe specific embodiments described therein. On the other hand, it willbe apparent to those skilled in the art that, subject to the limitationsset forth in the general description, the materials and proportions maybe considerably varied without departing from the spirit or scope ofthis invention.

From the preceding description, it will be apparent that this inventionprovides novel compositions of certain chlorofluoroalkanes and certainnitroalkanes which are resistant to the reaction which normally occursbetween said chlorofiuoroalkanes and primary and secondary alcohols.Therefore, there is provided a means whereby said chlorofluoroalkanescan be employed in conjunction with primary and secondary alcohols andmaintained in contact or admixture therewith for long periods of timewithout the aforesaid undesirable reactions taking place. Accordingly,it will be apparent that this invention constitutes a valuable advancein and contribution to the art.

This is a continuation-in-part of my copending application Serial No.28,222, filed May 11, 1960, and now abandoned.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of a chlorofluoroalkane of the groupconsisting of trichloroiluorornethane, trichlorotrifluoroethanes andtetrachlorodifiuoroethanes and from about 0.1% to about 5% by weight ofmononitroalkane of 1 to 3 carbon atoms.

2. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of trichlorofluoromethane and fromabout 0.1% to about 5% by weight of a mononitroalkane of 1 to 3 carbonatoms.

'3. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of trichlorofluoromethane'and fromabout 0.1% to about 5% by weight of 'nitromethane.

4. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of trichlorofluoromethane and fromabout 0.1% [to about 5% by weight of nitroethane.

5. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of trichlorofluoromethane and fromabout 0.1% to about 5% by weight of 2-nitropropane.

6. A composition resistant to reaction with primary and secondaryalcohols which consists essentially of trichlorofluoromcthane and fromabout 0.1% to about 5% by weight of l-nitropropane.

References Cited in the file of this patent UNITED STATES PATENTS2,163,899 Walker et al June 27, 1939 2,185,238 Whaley Jan. 2, 19402,567,621 Skeeters et a1. Sept. 11, 1951 2,952,547 Hill Sept..13, 19602,983,650 Rubin May 9, 1961

1. A COMPOSITION RESISTANT TO REACTION WITH PRIMARY AND SECONDARYALCOHOLS WHICH CONSISTS ESSENTIALLY OF A CHLOROFLUOROALKANE OF THE GROUPCONSISTING OF TRICHLOROFLUOROMETHANE, TRICHLOROTRIFLUOROETHANES ANDTETRACHLORODIFLUOROETHANES AND FROM ABOUT 0.1% TO ABOUT 5% BY WEIGHT OFMONONITROALKANE OF 1 TO 3 CARBON ATOMS.